ILLUSTRATIONS. 



Page. 



Plate I. Mountains north of Mount Holmes 4 



II. Paleozoic section, Crowfoot Ridge 8 



III. Geological cross sections of Gallatin Range 12 



IV. Panoramic view of Gallatin Range from Norris Geyser Basin 18 



V. Cross sections showing Mount Holmes bysmalith 18 



VI. Antler Peak from valley 22 



VII. Three River Peak from Gallatin Valley 24 



VIII. Bannock Peak from Panther Creek Valley 32 



IX. Geological cross sections 50 



X. Geological map of Gallatin Range 56 



XI. Photomicrographs of audesite-porphyry and dacite-porphyry 62 



XII. View of Echo Peak 68 



XIII. Electric Peak from Sepulchre Mountain 90 



XIV. Head of East Gulch of Electric Peak 90 



XV. Sepulchre Mountain from its northwest spur 96 



XVI. Geological map of Electric Peak and Sepulchre Mountain 96 



XVII. Diorites 100 



XVIII. Granite and diorite-porphyry 100 



XIX. Photomicrographs of andesite-porphyry and diorite 104 



XX. Photomicrographs of diorite and diorite-porphyry 104 



XXI. Photomicrographs of diorite-porphyry and dacite 104 



XXII. Photomicrographs of pyroxene-andesite and dacite 130 



XXIII. Map of the northern end of the Teton Range 150 



XXIV. Snake River Hot Springs 178 



XXV. Outlet Canyon 194 



XXVI. BaronettPeak 204 



XXVII. Geological map showing dissected volcano of C'randall Basin, Wyoming 216 



XXVIII. Index Peak 218 



XXIX. The Thunderer and Mount Norris 222 



XXX. Hoodoos 222 



XXXI. Hurricane Ridge 226 



XXXIi. Geological cross sections 232 



XXXIII. Photomicrographs of gabbro, diorite, and granitic aplite 250 



XXXIV. Photomicrographs of monzouite, diorite, and basalt 250 



XXXV. Eagle Peak 296 



XXXVI. Photomicrographs of absarokite 332 



XXXVII. Photomicrographs of shoshonite and diorite-porphyry 344 



XXXVIII. Photomicrographs of banakite, quartz-banakite, and andesito 350 



XXXIX. Obsidian Cliff columns 360 



XL. Top of columns 360 



XLI. LithophyBai 364 



XI 



